Concrete is by some estimates the most-used man-made material on the planet when measured by weight. Concrete typically constitutes water, aggregate, and cementitious material. The aggregate component of concrete is typically made up of gravel, sand, and/or crushed rock conforming to standard size distribution profiles, or gradations. The cementitious component of concrete is often made up of Portland Cement, produced according to standard processes. The water, aggregate, and cement can be mixed, placed, and allowed to cure over a period of time to form finished structural concrete.
Concrete is known to have relatively high compression strength but relatively low tensile strength and ductility. Accordingly, structural concrete often incorporates reinforcement having higher tensile strength and ductility than concrete, with steel reinforcing bars (rebar) being a particularly well-suited reinforcing material. Typically, in fabricating reinforced concrete structures, a rebar cage can be created inside formwork, and the concrete can be placed and allowed to cure around the rebar within the formwork. The strength and efficiency of reinforced concrete can depend on the transfer of stresses between the concrete and the rebar, and thus the bond strength developed between them.